title: Temporal control of contractile ring assembly by Plo1 regulation of myosin II recruitment by Mid1/anillin.
abstract: In eukaryotes, cytokinesis generally involves an actomyosin ring, the contraction of which promotes daughter cell segregation. Assembly of the contractile ring is tightly controlled in space and time. In the fission yeast, contractile ring components are first organized by the anillin-like protein Mid1 into medial cortical nodes. These nodes then coalesce laterally into a functional contractile ring. Although Mid1 is present at the medial cortex throughout G2, recruitment of contractile ring components to nodes starts only at mitotic onset, indicating that this event is cell-cycle regulated. Polo kinases are key temporal coordinators of mitosis and cytokinesis, and the Polo-like kinase Plo1 is known to activate Mid1 nuclear export at mitotic onset, coupling division plane specification to nuclear position. Here we provide evidence that Plo1 also triggers the recruitment of contractile ring components into medial cortical nodes. Plo1 binds at least two independent sites on Mid1, including a consensus site phosphorylated by Cdc2. Plo1 phosphorylates several residues within the first 100 amino acids of Mid1, which directly interact with the IQGAP Rng2, and influences the timing of myosin II recruitment. Plo1 thereby facilitates contractile ring assembly at mitotic onset.
authors.affiliation: Institut Curie, Centre de Recherche F-75248 Paris, France.
authors.forename: Maria
authors.initials: M
authors.lastname: Almonacid
authors.forename: Séverine
authors.initials: S
authors.lastname: Celton-Morizur
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Jakubowski
authors.forename: Florent
authors.initials: F
authors.lastname: Dingli
authors.forename: Damarys
authors.initials: D
authors.lastname: Loew
authors.forename: Adeline
authors.initials: A
authors.lastname: Mayeux
authors.forename: Jun-Song
authors.initials: JS
authors.lastname: Chen
authors.forename: Kathleen L
authors.initials: KL
authors.lastname: Gould
authors.forename: Dawn M
authors.initials: DM
authors.lastname: Clifford
authors.forename: Anne
authors.initials: A
authors.lastname: Paoletti
mesh_terms: D000205:Actomyosin / Q000378:metabolism / Q000502:physiology*; D001665:Binding Sites / Q000235:genetics; D016203:CDC2 Protein Kinase / Q000378:metabolism; D003285:Contractile Proteins / Q000378:metabolism*; D048749:Cytokinesis / Q000502:physiology*; D047468:Immunoprecipitation; D013058:Mass Spectrometry; D008856:Microscopy, Fluorescence; D024462:Myosin Type II / Q000378:metabolism*; D010766:Phosphorylation; D010957:Plasmids / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D012568:Schizosaccharomyces / Q000502:physiology*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D059008:Time-Lapse Imaging
chemical_list: D003285:Contractile Proteins; C489694:Mid1 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; C095886:anillin; D000205:Actomyosin; C501407:Plo1 protein, S pombe; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase; C469447:cdc2 protein, S pombe; D024462:Myosin Type II